Dent removal device

ABSTRACT

An elongated cylinder incorporating a forwardly projecting workpiece engaging screw member manipulable by an enlarged handwheel. A hammer is slidably positioned within the cylinder and, through a valve controlled fluid system, is moved forward into a releasable mounted position at the forward end of the cylinder and rearward, under increased pressure, so as to deliver a substantial impact blow on a rearwardly located anvil or abutment.

'United States Patent 1191 Jarman Dec. 2, 1975 1 1 DENT REMOVAL DEVICE[75] Inventor: Davis R. Jarman, Brunswick, Ga.

[73] Assignee: Virgil l-linson, Brunswick, Ga. a

part interest 122] Filed: Dec. 6, I973 [21] Appl. No.: 422,187

3,137,483 6/1964 Zinkiewicz 173/91 X 3,269,223 8/1966 Pawloski....91/466 X 3.323.346 6/1967 Spangler.... 1 72/407 3.326.304 6/1967Johnson..... 173/170 X 3,476,015 11/1969 Ackley.... 91/446 X 3,570,2893/1971 Smyers 72/705 3,657,917 4/1972 Chelminski 72/453 3,744,291 7/1973Hagcrty Ct 2117 72/705 X 3,777,621 12/1973 Blok Ct 31. 1. 91/446 XPrimary Examiner-C. W. Lanham Assistant Examiner-D. M. Gurley Attorney,Agent, or FirmClarence A. OBrien; Harvey B. Jacobson [57] ABSTRACT [56]References Cited An elongated cylinder incorporating a forwardly pro-UNITED STATES PATENTS jecting workpiece engaging screw member manipula-152391 6/1874 Manson 173/132 x eniarged f A hammer Shdably 1 292 4291/1919 Bull 1 173/132 x Posltloned Wlthm the cylmder n hrough a valve-1,313.353 2/1920 Nurnberger... 91/446 Controlled fluid System is movedforward into a 1,604,958 11/1926 Bayles.. 173/132 x leasable mountedPosition at the forward end of the 2,396,562 3/1946 Forss 1 72/407cylinder and rearward, under increased pressure, so as 2,457,930 1/1949Smith..... 29/252 X to deliver a substantial impact blow on a rearwardly2,715,913 Taylor located anvil or abutn1ent 2,933,068 4/1960 Johnson eta1... 173/133 2,934,984 5/1960 Woodman 81/5235 X 4 Claims, 4 DrawingFigures m Ill/ll/l/ll/I/l/l/l/l/ll, 40 36 k h 66 I 6 32 5 74 64 42 70 IR.Wl/RCE DENT REMOVAL DEVICE The present invention relates to new anduseful improvements in powered dent removal devices.

It is a primary object of the present invention to provide a dentremoving tool which utilizes a pressure moved sliding weight to developthe force required to reform the metal sheet or the like to effect thedesired straightening thereof. While the basic idea of using a slidingweight for this purpose is known, the known devices in most cases are ofcumbersome construction both difficult to attach to the workpiece andinherently unsafe in that the weight is exposed and hand manipulated.Such known devices are also frequently difficult to operate,particularly in other than a horizontal position.

The dent removal device of the present invention is unique in overcomingthe deficiencies of the known de vices. More particularly, theattachment of the device to the workpiece is simply effected through anenlarged handwheel which enables an attachment of the forward orworkpiece gripping portion of the device without an awkward manipulationof the entire device. Once attached, the tool can be, through the use ofair pressure, operated by a single hand and, in connection therewith,can be utilized in any position, including a vertical position wherein adownward pull is desired. As indicated, the device uses a sliding weightor hammer. However, as opposed to conventional dent removal tools, theweight herein is completely concealed within a housing or air cylinderwhereby any danger of the moving weight contacting the hand or hands ofthe user of the tool is completely avoided.

The device itself is of a compact and relatively simple, although highlyunique, construction and utilizes a structural arrangement which willprovide trouble-free service.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

FIG. 1 is a perspective view of the tool of the present invention;

FIG. 2 is an enlarged cross-sectional detail through the toolillustrating the control valve in a neutral position;

FIG. 3 is a cross-sectional view similar to FIG. 2 wherein the valve isshifted to an initial position which moves the hammer to its starting orcocked position; and

FIG. 4 is a similar view wherein the valve has been further shifted tothe hammer driving position.

Referring now more specifically to the drawings, reference numeral isused to generally designate the dent removing tool or device comprisingthe present invention. This tool 10 includes an elongated hollow body orcylinder 12 having an enlarged gripping and manipulating handle 14mounted at one end thereof and a workpiece engaging member 16 mounted atthe second end thereof.

The opposed ends of the cylinder 12 are internally threaded with thehandle mounting end, designated by reference numeral 18, constitutingthe rear end of the cylinder and with the workpiece mounting end,designated by reference numeral 20, constituting the forward end of thecylinder.

The workpiece engaging member 16 is in the nature of a tapered threadedmetal screw which includes an enlarged head portion 22 having arearwardly projecting enlarged key or rib 24 seated within a transverseslot defined within the forward end of an elongated threaded shaft 26.The shaft 26 projects integrally from an enlarged block 28 rotatablyretained within the forward end portion of the cylinder 12 by a combinedend plate and bearing 30 threaded within the internally threaded endportion 20 of the cylinder 12. This bearing 30 includes a peripheralflange which seats against the extreme end of the cylinder 12 and aninternal seat or socket which rotatably receives the block 28. Aninstepped portion 32 is provided between the block 28 and the externallythreaded shaft 26 so as to define a seating shoulder 36 slightly forwardof the combined end plate and bearing 30. An enlarged handwheel 38 isthreaded or otherwise locked to the shaft 26 against the shoulder 36with this handwheel 38 and the workpiece engaging screw 16 being fixedto the shaft 26 by an internally threaded cap 40 which clamps thehandwheel 38 against the shoulder 36 and similarly locks the enlargedribbed head 22 of the screw 16 to the end of the shaft 26. As will beappreciated, the end of the cap 40 is of course apertured so as to allowthe tapered screw 16 to project forwardly therebeyond for engagementwith the workpiece. Constructed in this manner, it will be appreciatedthat the screw 16 can be affixed to the workpiece, generally designatedby reference numeral 42, through merely a manipulation of the handwheel38 without requiring a manipulation of the entire tool 10. Basically, inattaching the screw 16, a small hole will be drilled through theworkpiece 42, this normally constituting the dent which is to beremoved. Then, through a manipulation of the handwheel 38, the taperedscrew 16 is screwed into the formed hole, this screw being self-tappingin nature so as to provide for a positive interlocking with theworkpiece 42.

Alternatively, the screw 16 can be made with a sharpened point so thatwhen the tool was cocked, the weight of the piston will drive the pointthrough the sheet metal whereby the screw can be screwed into the metalwithout having to perform the additional step of drilling a hole in thesheet metal. Likewise, the tool can be used to pull bearings and sealsin addition to its dent removal functions by utilizing an appropriatework engaging head thereon.

The force necessary to outwardly draw the dent is achieved by a slidingweight or hammer 44 provided within the cylinder 12. Manipulation of thehammer 44 is effected by a valve controlled air pressure system. Thissystem is incorporated within the handle 14 which includes an elongatedvalve chamber 46 orientated transversely across the rear end 18 of thecylinder 12, a handgrip portion 48 rearwardly thereof, and an integralexternally threaded forwardly projecting anvil or abutment definingportion 50 which threads within the rear portion 18 of the cylinder 12for effecting a locked mounting of the handle 14 on the cylinder 12 inconjunction with a closing of the rear portion of the cylinder. Theabutment 50 includes an air port 52 centrally therethrough. The chamber46 includes an upper bleed port 54 in generally aligned relation withthe abutment port 52 and a second smaller bleed port 56 located belowthe cylinder 12. Aligned with this second smaller bleed port 56 is anelongated air line 58 which extends from communication with the valvechamber 46 forwardly and into communication with the forward end of thecylinder 12 immediately inward of the block 28 and cylinder end closingbearing 30. The lower end of the chamber 46 is provided with an enlargedinlet 60 and is adapted to threadedly mount a line 62 extending from anappropriate source of pressurized air.

Provided within the valve chamber 46 is an elongated valve or valvemember 64 mounted for controlled longitudinal reciprocation thereinthrough the combined action of an expanded coiled compression spring 66engaged between the upper end of the chamber and the top of the valve 64and a pivoted trigger 68 also engaging the upper end of the valve 64. Aswill be appreciated, an outward swinging of the trigger 64 toward thehandgrip portion 48 of the handle 14 will effect an upward sliding ofthe valve 64 against the biasing force of the spring 66 with a relaxingof the force on the trigger 68 causing a downward or opposite movementof the valve 64 under the influence of the spring 66.

An axial bore extends inwardly through the lower end of the valve 64 atthe inlet end of the chamber 60 and terminates short of the inner end ofthe valve in a laterally directed passage 68 which, in the lowermost orneutral position of the valve 64, as illustrated in FIG. 2, isorientated below the abutment port 52 with the abutment closing theouter end of the passage 68. A second passage 70 extends laterally fromthe axial bore 66 at a point just inward of the inlet end thereof. Afirst annular passage 72 surrounds the valve 64 below the lateralpassage 68 and a second annular passage 74 surrounds the valve 64immediately above the passage 70 and, in the position of FIG. 2, belowthe bleed port 56.

In operation, the spring 66 in its fully expanded position retains thevalve in the position of FIG. 2 wherein the bleed ports, abutment port52 and air line 58 are respectively sealed off from the valve passagesand hence the air supply.

With reference to FIG. 3, an initial movement of the trigger 68 raisesthe valve 64 so as to align the passage 68 with the abutment port 52 andsimultaneously align the annular valve passage 74 with the adjoining endof the air line 58 and the small bleed port 56 aligned therewith. Inthis position, the pressurized air is introduced into the rear of thecylinder behind the hammer 44 resulting in a forward driving of thehammer 44 with the relatively small bleed port 56 providing for acomparatively soft movement of the hammer 44. At the forwardmostposition of the hammer 44, the hammer releasably interlocks with arearwardly extending ball 76 integrally formed with the block 28 andrearwardly spaced therefrom. The hammer 44 includes a ball conformingsocket 78, the entrance to which is resiliently restricted by anappropriate seal, O-ring, or the like 80 whereby a releasablesnap-locking of the hammer 44 to the forward end of the cylinder iseffected. In this manner, the hammer is retained at the forward end ofthe cylinder regardless of the orientation of the tool 10. Incidentally,it will be noted that this interengagement of the hammer 44 and the ball76 positions the hammer 44 slightly from the block 28 with the forwardend of the air line 58 communicating with the cylinder between thehammer 44 and the block 28.

With reference to FIG. 4, when the powered rearward driving of thehammer 44 is desired so as to effect a pull on the workpiece engagedscrew 16, the pull on the trigger 68 is continued so as to furtherupwardly shift the valve 64 with the lower air passage 70 aligning withthe air line 58 for the introduction of a flow of pressurized air intothe forward portion of the cylinder 12 between the hammer 44 and theblock 28. At the same time, the upper annular passage 72 communicatesthe abutment port 52 directly with the upper bleed port 54 for anexhausting of the air between the hammer 44'and the abutment or anvil50. The releasable interlocking of the hammer 44 and ball 76, inaddition to facilitating a use of the tool in any desired orientation,also provides a means for allowing a small buildup of pressure forwardof the hammer 44 prior to a snap-release of the hammer 44 which tends toincrease the force of the impact against the abutment or anvil 50. Thehammer, upon striking the abutment 50, causes a rearward jerk on thetool and a corresponding outward pulling of the workpiece 42, normally adent which is to e straightened.

Upon release of the trigger, the valve 64 will move past the position ofFIG. 3 tending to reposition the hammer 44 in its forward ball lockedposition preparatory to another rearward power driving of the hammer. Itwill be appreciated that the ball 76 and mating pocket 78 are sphericalwhereby a rotation of the ball 76, such as will occur upon a setting ofthe screw 16 through a manipulation of the handwheel 38 will not affectthe alignment of the ball and socket. In fact, depending upon theparticular tolerances involved, the ball 76 may rotate within the socket78 or the hammer 44, if locked to the ball 76, rotate with the screw 16upon manipulation of the handwheel 38.

From the foregoing, it should be appreciated that a highly unique dentremoving device has been defined. This device incorporates an air drivenhammer which is completely concealed and which exerts a pulling forcethrough a separately manipulable workpiece engaging member. The tool isusable in any position with the hammer being stabilized in a cocked orready position at the forward end of the device through a releasableinterlock. Operation of the device is effected through a simple triggercontrol which shifts a valve progressively through a series of stepswhich initially position the hammer at the forward end of the deviceadjacent the workpiece engaged member and subsequently forciblyrearwardly drives the hammer to effect a rearward forcing of the entiretool and attached workpiece.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scop of the invention.

What is claimed as new is as follows:

1. A fluid actuated hand tool for dent removal and the like comprisingan elongated cylinder including forward and rear ends, a workpieceengaging element mounted on and projecting forwardly from the forwardend of the cylinder, a longitudinally slidable hammer positioned within,said cylinder, a first fluid port through the cylinder at the rear endthereof, a second fluid port through the forward end, of said cylinder,a source of pressurized fluid, valve means selectively communicating thesource of pressurized fluid with said first fluid port for a forwardpositioning of said hammer within the cylinder and with said secondfluid port for a rearward driving of said hammer, abutment means at therear of said cylinder receiving the impact of the rearwardly drivenhammer, and lock means at the forward end of the cylinder forautomatically engaging and releasably securing said hammer upon aforward positioning of the hammer, said second fluid port being locatedforward of said lock means with release of said lock means beingeffected in response to communication of the source of pressurized fluidwith the second fluid port and a small buildup of pressure forward ofthe hammer, said workpiece engaging element comprising a threaded memberfor rotational driving into a workpiece aperture, and means forrotatably driving said threaded member independently of the remainder ofthe tool, the means for rotatably driving said threaded membercomprising mounting means rotatably locking the threaded member to theforward end of the cylinder for rotation of the threaded member relativeto the cylinder, and an enlarged handwheel locked to the mounting meansfor a rotational manipulation thereof.

2. The tool of claim 1 wherein said lock means comprises an enlargedball rigid with and projecting internally of the forward end of thecylinder, said hammer having an internal socket receiving said ball upona forward movement of the hammer and resilient means releasablyretaining the socket about said ball.

3. The tool of claim 2 wherein said valve means includes an elongatedvalve chamber, an elongated valve longitudinally shiftable within saidchamber, said first and second fluid ports communicating with saidchamber at spaced points therealong, said chamber including a bleed portgenerally coplanar with and angularly spaced from each fluid port, airpassage means within said valve, a fluid inlet in said chambercommunicating said chamber with said source of pressurized fluid, andmeans for selectively shifting said valve within said chamber for aselective communication of the air passage means with one of said fluidports while the second of said fluid ports is communicated with itsassociated bleed port.

4. The tool of claim 3 including a handle mounted on the rear of saidcylinder, said handle incorporating said valve chamber and including ahand grip spaced from said valve chamber and a trigger control for thevalve

1. A fluid actuated hand tool for dent removal and the like comprisingan elongated cylinder including forward and rear ends, a workpieceengaging element mounted on and projecting forwardly from the forwardend of the cylinder, a longitudinally slidable hammer positioned withinsaid cylinder, a first fluid port through the cylinder at the rear endthereof, a second fluid port through the forward end of said cylinder, asource of pressurized fluid, valve means selectively communicating thesource of pressurized fluid with said first fluid port for a forwardpositioning of said hammer within the cylinder and with said secondfluid port for a rearward driving of said hammer, abutment means at therear of said cylinder receiving the impact of the rearwardly drivenhammer, and lock means at the forward end of the cylinder forautomatically engaging and releasably securing said hammer upon aforward positioning of the hammer, said second fluid port being locatedforward of said lock means with release of said lock means beingeffected in response to communication of the source of pressurized fluidwith the second fluid port and a small buildup of pressure forward ofthe hammer, said workpiece engaging element comprising a threaded memberfor rotatioNal driving into a workpiece aperture, and means forrotatably driving said threaded member independently of the remainder ofthe tool, the means for rotatably driving said threaded membercomprising mounting means rotatably locking the threaded member to theforward end of the cylinder for rotation of the threaded member relativeto the cylinder, and an enlarged handwheel locked to the mounting meansfor a rotational manipulation thereof.
 2. The tool of claim 1 whereinsaid lock means comprises an enlarged ball rigid with and projectinginternally of the forward end of the cylinder, said hammer having aninternal socket receiving said ball upon a forward movement of thehammer and resilient means releasably retaining the socket about saidball.
 3. The tool of claim 2 wherein said valve means includes anelongated valve chamber, an elongated valve longitudinally shiftablewithin said chamber, said first and second fluid ports communicatingwith said chamber at spaced points therealong, said chamber including ableed port generally coplanar with and angularly spaced from each fluidport, air passage means within said valve, a fluid inlet in said chambercommunicating said chamber with said source of pressurized fluid, andmeans for selectively shifting said valve within said chamber for aselective communication of the air passage means with one of said fluidports while the second of said fluid ports is communicated with itsassociated bleed port.
 4. The tool of claim 3 including a handle mountedon the rear of said cylinder, said handle incorporating said valvechamber and including a hand grip spaced from said valve chamber and atrigger control for the valve means.